Devices of the above mentioned kind are well known. In connection with the operation of such a device, the material flow which is to be divided will quite often not be evenly distributed across the length of the dividing edge, and this means that the material strikes some areas more frequently than others. As a result, there will also be variations in the wear on the dividing edge across its length, which is a significant disadvantage in regard to the service life of the dividing edge and thus the actual time of operation of the device between two shutdowns for maintenance.